How can I use my player data from one account in a different account?

Solution 1:

Can I run my previous Minecraft installation(s) with a new account?

Assuming you buy the same version (i.e. Java Edition), yes. You'll just need to log in with the new credentials. You may need to download the latest Launcher, but the actual Minecraft app should not need re-downloading.

Will I need to rename the dat files tn the playerdata folder with my new ID?

This question seems to suggest yes. If you don't know the IDs, you should be able to note what the existing file is, join with your new account, and see what new file was added. The new file should be your new ID and the other should be your old one.

Alternatively, there may be mods out there that allow you to access other player's inventories. For example, NBTExplorer

Is the format just "<id>.dat"?

From this Reddit post:

In single player your data is stored in level.dat - the external (UUID).dat player files are only used if someone else joins the single player world in LAN mode.

Do I need to do anything else to move my player data to a new account?

You will likely lose capes that are saved on Minecraft's servers. You may be able to contact support to get them transferred. Aside from those, if you had a uploaded skin, you may need to re-add it using this link

Are there any known bugs/issues that doing this may cause?

Based on the Reddit post above, there may be issues transferring XP, recipes, and advancements.

Is it the same with servers and modded installations?

Assuming you own the server, you should be able to adjust the files in the same way. If not, you'll need to talk to the server admins to see if they will transfer your player data. Knowing your old and new IDs would be helpful, if not necessary, for this.

Solution 2:

Some things I'd like to add/mention/correct:

• The playerdata folder is only used on servers. There doesn't seem to be a need to modify it for a single player world.

• The files in the advancements and stats folders must be remaimed for advancements and stats to carry over.

• Pets don't seem to remember you, it seems you will have to edit the NBT data for objects separate from the player if you want to fully move accounts.

Full report:

I looked up the level.dat format on the wiki, and it didn't seem to contain any name/id data, so I decided to see if it would just automatically let me use my old data. I loaded up my installation, and it worked fine. My settings were as I left them.

I started by going into my older hardcore world to see if it would keep me in spectator mode and it did, so it seemed at least some of the player data carries over.

I then went into another world. I still had my inventory and exp, but my achievements were bugged. This was a simple fix. I just renamed the file in the achievements folder as I had intended to do with the playerdata folder.

Finally, I went into my current hardcore world. I noticed that I didn't have my recipes and I couldn't use the dog, but everything that had worked was already enough for me.

See https://minecraft.fandom.com/wiki/Player.dat_format#NBT_Structure